[A case of vascular parkinsonism associated with hyperhomocysteinemia and methylenetetrahydrofolate reductase gene variant (C677T)].

A 56-year-old man, who presented with 6 years history of difficulty in walking, was diagnosed as having vascular parkinsonism on the basis of the clinical findings of parkinsonism, pyramidal sign and the brain MRI findings of multiple lacunar infarction. Although he did not have hypertension, he had hyperhomocysteinemia and homozygous methylenetetrahydrofolate reductase (MTHFR) gene variant (C677T) as risk factors for ischemic stroke. Recent studies have shown that hyperhomocysteinemia and MTHFR gene variant are associated with small-vessel disease, suggesting that these risk factors may underlie vascular parkinsonism, particularly in patients lacking hypertension and in those with a relatively younger age at onset of this disease.